Lesson starter Explain how phagocytes work Why do

Lesson starter • Explain how phagocytes work • Why do we rarely get infected with the same infection twice?

Cells Alive FIGHTING BACK!

Today we are going to. . • Learn about transplants • Learn about vaccinations

Think. . Pair. . Share If your immune system can tell the difference between what is yours and not yours then this can cause a problem. What is it ?

Transplanted Organs A transplanted organ does not belong to you and your immune system can attack and destroy the organ called rejection

Organ Transplants The waiting list. . • You go onto the transplant waiting list while doctors try to find an organ that is a good match for you. • Although organs from different people work in the same way, there are some differences between them • They are differences in the antigens on the outside of cells. • If antigens on donor organ are different from your own then your body will attack the new organ (and treat it as an invader)

Size matters! The size and age of the donor is also important in matching. For example, a big heart wouldn't fit into a small body, and a small heart wouldn't pump enough blood for a big body!

What happens next? • Once an organ has been removed from a donor, is has to be transplanted quickly so that it will still work. If the donor isn't in the same hospital as you, it will be sped to you by motorbike, car, helicopter or even aeroplane!

What happens next? • Under general anaesthetic, the surgeon will go inside and disconnect all the plumbing and blood vessels from the old organ. • The new organ will be inserted once the old organ has been removed, and all the pipes and blood vessels will be reconnected

Stopping rejection • Unless the donor is your twin, finding an exact match is very unlikely • This means that your new organ will still have some foreign antigens, so your immune system might still attack it. This is called transplant rejection. To stop this from happening, the doctor will give medicines called IMMUNOSUPPRESSENTS

Immunosuppressants A drug which lowers the efficiency of the immune system Why may this be a problem?

Vaccination • Vaccines are a way of making the body produce antibodies without the risk of catching the disease. • You are injected with a harmless version of a microbe but your body still makes antibodies.

Vaccination • If a harmful version of the microbe does invade your body you will already have antibodies to kill it and wont get sick. • Common vaccines used today are the MMR (measles, mumps and rubella) and polio

The discovery of vaccination Watch the video and take notes in your jotter about the discovery of vaccines

Vaccination • Who developed vaccines? • What type of virus was the first vaccine for? • What type of people were immune to the virus? • How was this information used?

Write a summary about the discovery of vaccines